Re: [PATCH] drm/vc4: dsi: Only register our component once a DSI device is attached

[Maxime Ripard]

Hi Laurent,

On Sun, Jun 20, 2021 at 04:44:33AM +0300, Laurent Pinchart wrote:
> Hi Maxime,
> 
> I'm testing this, and I'm afraid it causes an issue with all the
> I2C-controlled bridges. I'm focussing on the newly merged ti-sn65dsi83
> driver at the moment, but other are affected the same way.
> 
> With this patch, the DSI component is only added when the DSI device is
> attached to the host with mipi_dsi_attach(). In the ti-sn65dsi83 driver,
> this happens in the bridge attach callback, which is called when the
> bridge is attached by a call to drm_bridge_attach() in vc4_dsi_bind().
> This creates a circular dependency, and the DRM/KMS device is never
> created.

We discussed it on IRC, but it makes more sense here.

The thing is, that patch is fixing a circular dependency we discussed
with Andrzej a year ago:

https://lore.kernel.org/dri-devel/20200630132711.ezywhvoiuv3swo57@xxxxxxxxxxx/

It seems like we have to choose between having the panels or bridges
working :/

Maxime

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